Nitro malonates synthesis

Catalytic direct asymmetric Michael reactions Addition of unmodified ketone and aldehyde donors to alkylidene malonates and nitro olefins." Synthesis, No.9, Qun 18, 2004), pp. 1509-1521, ISSN 0039-7881... 

One effective method for synthesis of tryptophan derivatives involves alkylation of formamido- or acetamido- malonate diesters by gramine[l,2]. Conversion to tryptophans is completed by hydrolysis and decarboxylation. These reactions were discussed in Chapter 12. An enolate of an a-nitro ester is an alternative nucleophile. The products can be converted to tryptophans by rcduction[3,4],... 

Monoanions derived from nitroalkanes are more prone to alkylate on oxygen rather than on carbon in reactions with alkyl halides, as discussed in Section 5.1. Methods to circumvent O-alkylation of nitro compounds are presented in Sections 5.1 and 5.4, in which alkylation of the a.a-dianions of primary nitro compounds and radial reactions are described. Palladium-catalyzed alkylation of nitro compounds offers another useful method for C-alkylation of nitro compounds. Tsuj i and Trost have developed the carbon-carbon bond forming reactions using 7t-allyl Pd complexes. Various nucleophiles such as the anions derived from diethyl malonate or ethyl acetoacetate are employed for this transformation, as shown in Scheme 5.7. This process is now one of the most important tools for synthesis of complex compounds.6811-1 Nitro compounds can participate in palladium-catalyzed alkylation, both as alkylating agents (see Section 7.1.2) and nucleophiles. This section summarizes the C-alkylation of nitro compounds using transition metals. 

Urea may be recognised as a structural feature in the triketo form disconnection then reveals diethyl malonate as the other reagent. The synthesis of barbituric acid is therefore effected (Expt 8.36) by condensation of diethyl malonate with urea in the presence of sodium ethoxide. Barbituric acid undergoes nitration in the 5-position on treatment with fuming nitric acid, and reduction of the nitro derivative (98) yields 5-aminobarbituric acid (99) (uramil). 

The method has been extended to the synthesis of cyclic 1,1-enediamines with nitro and other electron-withdrawing substituents on the /f-carbon atom39,96. For example, l-methyl-2-methylthio-4,5-dihydroimidazoline (74) reacts with nitromethane, and diethyl malonate, malononitrile and alkyl cyanoacetates at 100 °C to yield products 75 in 56-78% yield (equation 25)39. 

The main synthesis of oxindoles is simple and direct and involves an intramolecular Friedel-Crafts alkylation reaction as the cyclising step. Also straightforward in concept is the displacement of halogen from an ort/to-halo-nitroarene with malonate, this leading to an oxindole after decarboxylation and reduction of the nitro group with spontaneous lactamisation. ... 

For the preparation of o- and p-nitroacetophenone by direct oximation of o- and -ethyl-nitrobenzene see page 430,213 and for synthesis by the malonic ester route from o- and p-nitro-benzoyl chloride see reference 214. 

Nitro- and 6-nitroveratric acids, prepared from vanillin by the method of R. Pschorr and C. Sumuleanu (29), were separately subjected to the Bischoff synthesis (27), their chlorides being condensed with diethyl malonate, and the products reduced, cyclized and decarboxylated by treatment with tin and aqueous-alcoholic hydrochloric acid. 

Another practically improved synthesis method is treating thiourea with dialkyl malonate following acidity by hydrogen chloride to construct 46, which produced intermediate 43 under the base condition (Scheme 13). ° The reduction of the nitro dichloropyrimidine thioether 45 was also conducted by using iron powder in acetyl acid. ... 

Literature procedures were employed in the synthesis of 4-amlno-3-hydroxybenzoic acid 1 (9) and 3-amlno-4-hydroxyphenylace-tic acid (10). The propanoic and propenoic compounds were obtained as outlined in Figure 1. In both Isomeric systems, the intermediate hydroxynitrobenzaldehydes were cleanly converted to the cinnamic acid derivatives by Knoevenagel condensation with malonic acid followed by spontaneous decarboxylation. Reduction of the nitro groups with sodium dithionate then gave the alkene... 

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